Data communication networks may include various computers, servers, nodes, routers, switches, hubs, proxies, and other devices coupled to and configured to pass data to one another. These devices are referred to herein as “network elements,” and may provide a variety of network resources on a network. Data is communicated through data communication networks by passing protocol data units (such as packets, cells, frames, or segments) between the network elements over communication links on the network. A particular protocol data unit may be handled by multiple network elements and cross multiple communication links as it travels between its source and its destination over the network. Hosts such as computers, telephones, cellular telephones, Personal Digital Assistants, and other types of consumer electronics connect to and transmit/receive data over the communication network and, hence, are users of the communication services offered by the communication network.
Network switches (Access Points, Mobility Switches, Edge Switches and the like) are typically implemented to have a control plane that controls operation of the network element and a data plane that handles traffic flowing through the network. The data plane typically will have a collection of line cards having ports that connect to links on the network. Data is received at a particular port, switched within the data plane, and output at one or more other ports onto other links on the network. To enable the data to be handled quickly, the data plane is typically implemented in hardware so that all of the decisions as to how to handle the data are performed using hardware lookups, etc.
Over time, the manner in which network elements handle data has evolved. For example, two or more physical links may extend between a group of network elements and be used collectively as a multi-link trunk (MLT). When the links of an MLT are physically connected to two different network elements, the MLT is referred to as a Split Multi-Link Trunk (SMLT).
As noted above, depending on the manner in which the network elements are interconnected, there may be many ways for the network element to forward a frame/packet to enable the frame/packet to reach its destination. As used herein, the term “cluster” is used to refer to one or more nodes providing node-level resiliency at the network level. Logical connections between the cluster nodes are referred to herein as Inter-Switch Trunks (ISTs). ISTs may be physical links that extend from one network element to a neighboring network element in the cluster, or may be logical links that tunnel through one or more intermediate network elements within the cluster. The node that receives a packet will be referred to as a local node. All other nodes within the cluster are referred to as remote nodes with respect to the received packet.
Wireless Local Area Network (WLAN) split-plane requires data plane or packet forwarding function of the WLAN end devices (mobility units) traffic being handled by the routing switches in the wired network rather than tunneling all the WLAN traffic to centralized controllers. These switches are called mobility switches and they are capable of terminating tunnels initiated by the WLAN access point (AP) devices. They perform the packet forwarding function for the WLAN network.
A significant number of deployments have (routed) split multi-link trunking (SMLT/RSMLT) in the distribution and core layers. (R)SMLT provides redundancy and traffic load balancing of the routing switch nodes. Typical WLAN split plane deployment in a customer network will prefer the mobility switch function be performed by a routing switch in the distribution or core layers. This essentially requires interworking between WLAN split plane and RSMLT. WLAN split plane is a unique solution to converge the wired and wireless networks. In these converged networks, wired network resiliency capabilities should be extended to the WLAN networks.